Controlled trials that investigated the efficacy of probiotics in maintaining remission in patients with ulcerative colitis were eligible for inclusion. Relapse was the main outcome of interest (defined as the appearance of symptoms and/or signs that needed additional medical treatment or any increase in colitis activity index to more than 4 points).
Included studies either compared probiotics with placebo or compared probiotics with mesalazine (doses ranged from 1,200mg/day to 2,400mg/day). Mean ages of patients ranged from 33.5 to 43.5 yeasr (where reported). Probiotics used were bifidobacteria, bifid triple viable capsule, Escherichia coli preparation and Lactobacillus GG. A variety of bacteria was named in the probiotics. Doses ranged from 1x1010 to 5x1010 viable bacteria per day. Treatment duration varied from two to 12 months. Where reported, patients were treated with various drugs before the study (including steroids, salicylates).
Three reviewers independently selected studies for inclusion.